The xanthenone acetic acid class of compounds have been shown to be of potential utility in cancer treatment. Of these, the compound 5,6-dimethylxanthenone-4-acetic acid (DMXAA) has been shown to have significant antitumour activity against murine tumours. Studies in animals have shown that this activity is a consequence of the induction of the cytokine tumour necrosis factor (TNF), particularly within tumour tissue, and of the consequent inhibition of tumour blood flow. To date, DMXAA has shown evidence of marginal clinical anti-cancer activity in humans.
The applicants have now surprisingly found that DMXAA amplifies the induction of TNF by cultured human peripheral blood cells in response to a variety of agents capable of inducing a second signal that by itself modulates TNF production. These include ligands that occupy external cellular receptors connected with the TNF induction pathway and compounds that modulate cellular biochemical pathways connected to TNF induction.
With the above background in mind, it is an object of the present invention to provide a method of treatment of cancer which will at least provide the public with a useful choice.